diff options
Diffstat (limited to 'src/include/common/jsonapi.h')
| -rw-r--r-- | src/include/common/jsonapi.h | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/src/include/common/jsonapi.h b/src/include/common/jsonapi.h index c524ff5be8b..167615a5576 100644 --- a/src/include/common/jsonapi.h +++ b/src/include/common/jsonapi.h @@ -92,9 +92,11 @@ typedef struct JsonIncrementalState JsonIncrementalState; * conjunction with token_start. * * JSONLEX_FREE_STRUCT/STRVAL are used to drive freeJsonLexContext. + * JSONLEX_CTX_OWNS_TOKENS is used by setJsonLexContextOwnsTokens. */ #define JSONLEX_FREE_STRUCT (1 << 0) #define JSONLEX_FREE_STRVAL (1 << 1) +#define JSONLEX_CTX_OWNS_TOKENS (1 << 2) typedef struct JsonLexContext { const char *input; @@ -130,9 +132,10 @@ typedef JsonParseErrorType (*json_scalar_action) (void *state, char *token, Json * to doing a pure parse with no side-effects, and is therefore exactly * what the json input routines do. * - * The 'fname' and 'token' strings passed to these actions are palloc'd. - * They are not free'd or used further by the parser, so the action function - * is free to do what it wishes with them. + * By default, the 'fname' and 'token' strings passed to these actions are + * palloc'd. They are not free'd or used further by the parser, so the action + * function is free to do what it wishes with them. This behavior may be + * modified by setJsonLexContextOwnsTokens(). * * All action functions return JsonParseErrorType. If the result isn't * JSON_SUCCESS, the parse is abandoned and that error code is returned. @@ -216,6 +219,25 @@ extern JsonLexContext *makeJsonLexContextIncremental(JsonLexContext *lex, int encoding, bool need_escapes); +/* + * Sets whether tokens passed to semantic action callbacks are owned by the + * context (in which case, the callback must duplicate the tokens for long-term + * storage) or by the callback (in which case, the callback must explicitly + * free tokens to avoid leaks). + * + * By default, this setting is false: the callback owns the tokens that are + * passed to it (and if parsing fails between the two object-field callbacks, + * the field name token will likely leak). If set to true, tokens will be freed + * by the lexer after the callback completes. + * + * Setting this to true is important for long-lived clients (such as libpq) + * that must not leak memory during a parse failure. For a server backend using + * memory contexts, or a client application which will exit on parse failure, + * this setting is less critical. + */ +extern void setJsonLexContextOwnsTokens(JsonLexContext *lex, + bool owned_by_context); + extern void freeJsonLexContext(JsonLexContext *lex); /* lex one token */ |